package cn.linstudy.utils;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * @Description
 * @Author XiaoLin
 * @Date 2021/3/21 15:27
 */
public class RelativeDateUtils {

  private static final long ONE_MINUTE = 60000L;
  private static final long ONE_HOUR = 3600000L;
  private static final long ONE_DAY = 86400000L;
  private static final long ONE_WEEK = 604800000L;

  private static final String ONE_SECOND_AGO = "秒前";
  private static final String ONE_MINUTE_AGO = "分钟前";
  private static final String ONE_HOUR_AGO = "小时前";
  private static final String ONE_DAY_AGO = "天前";
  private static final String ONE_MONTH_AGO = "月前";
  private static final String ONE_YEAR_AGO = "年前";

  public static void main(String[] args) throws ParseException, ParseException {
    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:sm");
    Date date = format.parse("2021-3-20 18:35:35");
    System.out.println(format(date));
  }

  public static String format(Date date) {
    long delta = new Date().getTime() - date.getTime();
    if (delta < 1L * ONE_MINUTE) {
      long seconds = toSeconds(delta);
      return (seconds <= 0 ? 1 : seconds) + ONE_SECOND_AGO;
    }
    if (delta < 45L * ONE_MINUTE) {
      long minutes = toMinutes(delta);
      return (minutes <= 0 ? 1 : minutes) + ONE_MINUTE_AGO;
    }
    if (delta < 24L * ONE_HOUR) {
      long hours = toHours(delta);
      return (hours <= 0 ? 1 : hours) + ONE_HOUR_AGO;
    }
    if (delta < 48L * ONE_HOUR) {
      return "昨天";
    }
    if (delta < 30L * ONE_DAY) {
      long days = toDays(delta);
      return (days <= 0 ? 1 : days) + ONE_DAY_AGO;
    }
    if (delta < 12L * 4L * ONE_WEEK) {
      long months = toMonths(delta);
      return (months <= 0 ? 1 : months) + ONE_MONTH_AGO;
    } else {
      long years = toYears(delta);
      return (years <= 0 ? 1 : years) + ONE_YEAR_AGO;
    }
  }

  private static long toSeconds(long date) {
    return date / 1000L;
  }

  private static long toMinutes(long date) {
    return toSeconds(date) / 60L;
  }

  private static long toHours(long date) {
    return toMinutes(date) / 60L;
  }

  private static long toDays(long date) {
    return toHours(date) / 24L;
  }

  private static long toMonths(long date) {
    return toDays(date) / 30L;
  }

  private static long toYears(long date) {
    return toMonths(date) / 365L;
  }


}

